Composite coating separator, method for preparing the same and lithium battery

Abstract

The present application relates to the technical field of battery separator, in particular to a kind of composite coating separator and its preparation method and lithium battery.The composite coating separator includes base film and coating layer arranged on at least one side surface of base film, and coating layer includes first binder and second binder, first binder includes HNBR, and second binder includes PVDF and / or PAA.Preparation method includes the following steps: first binder, second binder and first solvent, second solvent are mixed to form slurry, at least one side surface of base film is coated, after solidification bath treatment, it is dried, and the composite coating separator of the present application is obtained.By introducing HNBR in coating layer, the adhesion of the separator is significantly improved;The phase separation of first binder and second binder is used to form a porous double continuous structure, which improves the porosity of the separator, improves the air permeability of the separator, and has high ionic conductivity and low fluorine content, which is economical and environmentally friendly.

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